http://www.1up.com/do/newsStory?cId=3165391
Seems like the only thing they were planning on doinng was adding online play and removing the characters who did not want to make a re-appearance.
I would assume they would sharpen up the graphics and fix the framerate, but wasn't mentioned.
And who knows sometimes emulated software on XBLA has shown to be a bit... worse? I think the Sega games are victims of that though.